1. Field of the Invention
The present invention relates to an anodized article and method and more particularly, to aluminum-silicon alloys having a surface comprised of grown silicon dioxide crystals held in a supporting matrix of aluminum oxide, abrasive tools, aircraft skins, a solar energy absorbing article and method, and to methods of making the same.
2. Description of the Prior Art
Tools used by precision machinists and instrument makers are known to be difficult to use. Precise cuts with such tools often require years of experience by the user, as well as the use of a lubricant to prevent loading and binding. One difficulty in the manufacture of precision tools, particularly where the abrasive element consists of hard abrasive grits bonded to a tool body, is to form a bond which is strong enough to permit use of the tool for cutting and other similarly demanding operations. A number of fabrication techniques have been developed in an attempt to fashion a durable, abrasive tool. For example, according to one typical process, an abrasive grit is adhesively bonded to a supporting substrate. Another process presses, air blasts or rolls an abrasive grit onto the surface of an anodizable material like aluminum and then anodizes the surface to secure the abrasive grit. However, neither of these processes, nor, in fact, any other presently known method of fabrication can produce an abrasive tool having abrasive elements which are strongly enough bound to the tool base to make the tool desirable for cutting operations. Moreover, an abrasive grit rolled on, or adhesively bonded, to a tool works loose, is spread throughout the work-piece, e.g., diamond grit in a fine watch, and must be thoroughly cleaned out to avoid subsequent damage to the work-piece.
The physical properties of many materials severely limit their desired performance at high temperatures, and under high mechanical stress and strain. For instance, the properties of an aircraft skin in large part are a limitation on the performance capability of high speed aircraft. If an aircraft skin material were available that could withstand the mechanical stresses at higher ambient temperatures and had an optimum coefficient of thermal conductivity with a better coefficient of heat transfer than those materials commonly used, higher speeds at lower altitudes would be possible.
The collection of Solar Radiant Energy requires an energy absorbing panel or material that can withstand high temperatures without physical change, and all types of weather conditions without surface deterioration. Probably the best type collecting surface is described as a "black body", but ordinarily these are laboratory test units, and are not suitable for exposure to weather conditions for long time periods. If a solar energy absorbing material were available that approached the absorptive characteristics of a black body, which had excellent mechanical characteristics so that it could be exposed to the weather elements without deterioration, and which transferred the surface radiant energy to the energy transport fluid, to be used subsequently for the extraction of its heat energy, one of the main problems for the use of Solar Energy would be solved.